"Tacking never completely stopped, it went quiet for while, but now it seems to have ramped up again with a number of attacks in the last few weeks."

Police say some cyclists have sustained serious injuries as a result of the tacks which are so tiny they're almost impossible to see on the asphalt.

One cyclist who rode over a tack was thrown off his bike, broke his hip, and required surgery, Inspector Noy said.

He described the offending as 'mindless stupidty' which often targeted the community's most vulnerable.

People with disabilities and the elderly have also fallen victim with numerous reports of metal tacks puncturing the wheels of mobility scooters.

Inspector Noy said police had also received reports of young children wearing thongs being pierced in the foot by the tacks, while animals, particularly dogs walking along the track with their owners, had tacks stuck in their paws.

Other metal tacks have been found washed up in the river.

Despite numerous pleas for public assistance over the years, the Boulie Tacker has never been charged.

Inspector Noy said one of the biggest hurdles investigators faced was cyclists not reporting the incidents to police.

"It's really hard for us to actually track the exact movements of the culprit other than trawling through cycling pages on social media where the incidents are reported because people don't always contact police," he said.

"We are working with VicRoads who contracts sweepers to clear the paths so that we are able to actually track where these tacks are being dropped and to see if there is a pattern in offending."

He estimated that hundreds of thousands of dollars of taxpayer money had been pumped into sweeping Kew Boulevard to rid it off the metal tacks.

Inspector Noy said the culprit seemed to be targeting spots along the walking track at random.

Police also haven't ruled out the possibility there is more than one offender.

"The key message we want to get through to people is that this doesn't just impact cyclists," he said.

While the cost to cyclists could be huge, police had also invested enormous resources into the matter, "time that police could have spent investigating aggravated burglaries, assaults and sex offences," he said.

He believed an 'anti-cyclist' mentality in some pockets of the area had also stalled the investigation.

"I really appeal to every resident's sense of moral obligation as good member of the community," he said.

"There are people being hurt, property being damaged, taxpayers' dollars being wasted and if somebody has seen or heard something, no matter how small, I urge them to come forward because it could just be the trigger point that can resolve this ongoing scourge."

Anyone with information is urged to contact Crime Stoppers on 1800 333 000 or visit crimestoppersvic.com.au